// SPDX-License-Identifier: GPL-2.0-or-later /* * drivers/rtc/rtc-pl031.c * * Real Time Clock interface for ARM AMBA PrimeCell 031 RTC * * Author: Deepak Saxena <dsaxena@plexity.net> * * Copyright 2006 (c) MontaVista Software, Inc. * * Author: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com> * Copyright 2010 (c) ST-Ericsson AB */ #include <linux/module.h> #include <linux/rtc.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/amba/bus.h> #include <linux/io.h> #include <linux/bcd.h> #include <linux/delay.h> #include <linux/pm_wakeirq.h> #include <linux/slab.h> /* * Register definitions */ #define RTC_DR 0x00 /* Data read register */ #define RTC_MR 0x04 /* Match register */ #define RTC_LR 0x08 /* Data load register */ #define RTC_CR 0x0c /* Control register */ #define RTC_IMSC 0x10 /* Interrupt mask and set register */ #define RTC_RIS 0x14 /* Raw interrupt status register */ #define RTC_MIS 0x18 /* Masked interrupt status register */ #define RTC_ICR 0x1c /* Interrupt clear register */ /* ST variants have additional timer functionality */ #define RTC_TDR 0x20 /* Timer data read register */ #define RTC_TLR 0x24 /* Timer data load register */ #define RTC_TCR 0x28 /* Timer control register */ #define RTC_YDR 0x30 /* Year data read register */ #define RTC_YMR 0x34 /* Year match register */ #define RTC_YLR 0x38 /* Year data load register */ #define RTC_CR_EN (1 << 0) /* counter enable bit */ #define RTC_CR_CWEN (1 << 26) /* Clockwatch enable bit */ #define RTC_TCR_EN (1 << 1) /* Periodic timer enable bit */ /* Common bit definitions for Interrupt status and control registers */ #define RTC_BIT_AI (1 << 0) /* Alarm interrupt bit */ #define RTC_BIT_PI (1 << 1) /* Periodic interrupt bit. ST variants only. */ /* Common bit definations for ST v2 for reading/writing time */ #define RTC_SEC_SHIFT 0 #define RTC_SEC_MASK (0x3F << RTC_SEC_SHIFT) /* Second [0-59] */ #define RTC_MIN_SHIFT 6 #define RTC_MIN_MASK (0x3F << RTC_MIN_SHIFT) /* Minute [0-59] */ #define RTC_HOUR_SHIFT 12 #define RTC_HOUR_MASK (0x1F << RTC_HOUR_SHIFT) /* Hour [0-23] */ #define RTC_WDAY_SHIFT 17 #define RTC_WDAY_MASK (0x7 << RTC_WDAY_SHIFT) /* Day of Week [1-7] 1=Sunday */ #define RTC_MDAY_SHIFT 20 #define RTC_MDAY_MASK (0x1F << RTC_MDAY_SHIFT) /* Day of Month [1-31] */ #define RTC_MON_SHIFT 25 #define RTC_MON_MASK (0xF << RTC_MON_SHIFT) /* Month [1-12] 1=January */ #define RTC_TIMER_FREQ 32768 /** * struct pl031_vendor_data - per-vendor variations * @ops: the vendor-specific operations used on this silicon version * @clockwatch: if this is an ST Microelectronics silicon version with a * clockwatch function * @st_weekday: if this is an ST Microelectronics silicon version that need * the weekday fix * @irqflags: special IRQ flags per variant */ struct pl031_vendor_data { struct rtc_class_ops ops; bool clockwatch; bool st_weekday; unsigned long irqflags; time64_t range_min; timeu64_t range_max; }; struct pl031_local { struct pl031_vendor_data *vendor; struct rtc_device *rtc; void __iomem *base; }; static int pl031_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct pl031_local *ldata = dev_get_drvdata(dev); unsigned long imsc; /* Clear any pending alarm interrupts. */ writel(RTC_BIT_AI, ldata->base + RTC_ICR); imsc = readl(ldata->base + RTC_IMSC); if (enabled == 1) writel(imsc | RTC_BIT_AI, ldata->base + RTC_IMSC); else writel(imsc & ~RTC_BIT_AI, ldata->base + RTC_IMSC); return 0; } /* * Convert Gregorian date to ST v2 RTC format. */ static int pl031_stv2_tm_to_time(struct device *dev, struct rtc_time *tm, unsigned long *st_time, unsigned long *bcd_year) { int year = tm->tm_year + 1900; int wday = tm->tm_wday; /* wday masking is not working in hardware so wday must be valid */ if (wday < -1 || wday > 6) { dev_err(dev, "invalid wday value %d\n", tm->tm_wday); return -EINVAL; } else if (wday == -1) { /* wday is not provided, calculate it here */ struct rtc_time calc_tm; rtc_time64_to_tm(rtc_tm_to_time64(tm), &calc_tm); wday = calc_tm.tm_wday; } *bcd_year = (bin2bcd(year % 100) | bin2bcd(year / 100) << 8); *st_time = ((tm->tm_mon + 1) << RTC_MON_SHIFT) | (tm->tm_mday << RTC_MDAY_SHIFT) | ((wday + 1) << RTC_WDAY_SHIFT) | (tm->tm_hour << RTC_HOUR_SHIFT) | (tm->tm_min << RTC_MIN_SHIFT) | (tm->tm_sec << RTC_SEC_SHIFT); return 0; } /* * Convert ST v2 RTC format to Gregorian date. */ static int pl031_stv2_time_to_tm(unsigned long st_time, unsigned long bcd_year, struct rtc_time *tm) { tm->tm_year = bcd2bin(bcd_year) + (bcd2bin(bcd_year >> 8) * 100); tm->tm_mon = ((st_time & RTC_MON_MASK) >> RTC_MON_SHIFT) - 1; tm->tm_mday = ((st_time & RTC_MDAY_MASK) >> RTC_MDAY_SHIFT); tm->tm_wday = ((st_time & RTC_WDAY_MASK) >> RTC_WDAY_SHIFT) - 1; tm->tm_hour = ((st_time & RTC_HOUR_MASK) >> RTC_HOUR_SHIFT); tm->tm_min = ((st_time & RTC_MIN_MASK) >> RTC_MIN_SHIFT); tm->tm_sec = ((st_time & RTC_SEC_MASK) >> RTC_SEC_SHIFT); tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); tm->tm_year -= 1900; return 0; } static int pl031_stv2_read_time(struct device *dev, struct rtc_time *tm) { struct pl031_local *ldata = dev_get_drvdata(dev); pl031_stv2_time_to_tm(readl(ldata->base + RTC_DR), readl(ldata->base + RTC_YDR), tm); return 0; } static int pl031_stv2_set_time(struct device *dev, struct rtc_time *tm) { unsigned long time; unsigned long bcd_year; struct pl031_local *ldata = dev_get_drvdata(dev); int ret; ret = pl031_stv2_tm_to_time(dev, tm, &time, &bcd_year); if (ret == 0) { writel(bcd_year, ldata->base + RTC_YLR); writel(time, ldata->base + RTC_LR); } return ret; } static int pl031_stv2_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) { struct pl031_local *ldata = dev_get_drvdata(dev); int ret; ret = pl031_stv2_time_to_tm(readl(ldata->base + RTC_MR), readl(ldata->base + RTC_YMR), &alarm->time); alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI; alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI; return ret; } static int pl031_stv2_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) { struct pl031_local *ldata = dev_get_drvdata(dev); unsigned long time; unsigned long bcd_year; int ret; ret = pl031_stv2_tm_to_time(dev, &alarm->time, &time, &bcd_year); if (ret == 0) { writel(bcd_year, ldata->base + RTC_YMR); writel(time, ldata->base + RTC_MR); pl031_alarm_irq_enable(dev, alarm->enabled); } return ret; } static irqreturn_t pl031_interrupt(int irq, void *dev_id) { struct pl031_local *ldata = dev_id; unsigned long rtcmis; unsigned long events = 0; rtcmis = readl(ldata->base + RTC_MIS); if (rtcmis & RTC_BIT_AI) { writel(RTC_BIT_AI, ldata->base + RTC_ICR); events |= (RTC_AF | RTC_IRQF); rtc_update_irq(ldata->rtc, 1, events); return IRQ_HANDLED; } return IRQ_NONE; } static int pl031_read_time(struct device *dev, struct rtc_time *tm) { struct pl031_local *ldata = dev_get_drvdata(dev); rtc_time64_to_tm(readl(ldata->base + RTC_DR), tm); return 0; } static int pl031_set_time(struct device *dev, struct rtc_time *tm) { struct pl031_local *ldata = dev_get_drvdata(dev); writel(rtc_tm_to_time64(tm), ldata->base + RTC_LR); return 0; } static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) { struct pl031_local *ldata = dev_get_drvdata(dev); rtc_time64_to_tm(readl(ldata->base + RTC_MR), &alarm->time); alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI; alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI; return 0; } static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) { struct pl031_local *ldata = dev_get_drvdata(dev); writel(rtc_tm_to_time64(&alarm->time), ldata->base + RTC_MR); pl031_alarm_irq_enable(dev, alarm->enabled); return 0; } static void pl031_remove(struct amba_device *adev) { struct pl031_local *ldata = dev_get_drvdata(&adev->dev); dev_pm_clear_wake_irq(&adev->dev); device_init_wakeup(&adev->dev, false); if (adev->irq[0]) free_irq(adev->irq[0], ldata); amba_release_regions(adev); } static int pl031_probe(struct amba_device *adev, const struct amba_id *id) { int ret; struct pl031_local *ldata; struct pl031_vendor_data *vendor = id->data; struct rtc_class_ops *ops; unsigned long time, data; ret = amba_request_regions(adev, NULL); if (ret) goto err_req; ldata = devm_kzalloc(&adev->dev, sizeof(struct pl031_local), GFP_KERNEL); ops = devm_kmemdup(&adev->dev, &vendor->ops, sizeof(vendor->ops), GFP_KERNEL); if (!ldata || !ops) { ret = -ENOMEM; goto out; } ldata->vendor = vendor; ldata->base = devm_ioremap(&adev->dev, adev->res.start, resource_size(&adev->res)); if (!ldata->base) { ret = -ENOMEM; goto out; } amba_set_drvdata(adev, ldata); dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev)); dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev)); data = readl(ldata->base + RTC_CR); /* Enable the clockwatch on ST Variants */ if (vendor->clockwatch) data |= RTC_CR_CWEN; else data |= RTC_CR_EN; writel(data, ldata->base + RTC_CR); /* * On ST PL031 variants, the RTC reset value does not provide correct * weekday for 2000-01-01. Correct the erroneous sunday to saturday. */ if (vendor->st_weekday) { if (readl(ldata->base + RTC_YDR) == 0x2000) { time = readl(ldata->base + RTC_DR); if ((time & (RTC_MON_MASK | RTC_MDAY_MASK | RTC_WDAY_MASK)) == 0x02120000) { time = time | (0x7 << RTC_WDAY_SHIFT); writel(0x2000, ldata->base + RTC_YLR); writel(time, ldata->base + RTC_LR); } } } if (!adev->irq[0]) { /* When there's no interrupt, no point in exposing the alarm */ ops->read_alarm = NULL; ops->set_alarm = NULL; ops->alarm_irq_enable = NULL; } device_init_wakeup(&adev->dev, true); ldata->rtc = devm_rtc_allocate_device(&adev->dev); if (IS_ERR(ldata->rtc)) { ret = PTR_ERR(ldata->rtc); goto out; } ldata->rtc->ops = ops; ldata->rtc->range_min = vendor->range_min; ldata->rtc->range_max = vendor->range_max; ret = rtc_register_device(ldata->rtc); if (ret) goto out; if (adev->irq[0]) { ret = request_irq(adev->irq[0], pl031_interrupt, vendor->irqflags, "rtc-pl031", ldata); if (ret) goto out; dev_pm_set_wake_irq(&adev->dev, adev->irq[0]); } return 0; out: amba_release_regions(adev); err_req: return ret; } /* Operations for the original ARM version */ static struct pl031_vendor_data arm_pl031 = { .ops = { .read_time = pl031_read_time, .set_time = pl031_set_time, .read_alarm = pl031_read_alarm, .set_alarm = pl031_set_alarm, .alarm_irq_enable = pl031_alarm_irq_enable, }, .range_max = U32_MAX, }; /* The First ST derivative */ static struct pl031_vendor_data stv1_pl031 = { .ops = { .read_time = pl031_read_time, .set_time = pl031_set_time, .read_alarm = pl031_read_alarm, .set_alarm = pl031_set_alarm, .alarm_irq_enable = pl031_alarm_irq_enable, }, .clockwatch = true, .st_weekday = true, .range_max = U32_MAX, }; /* And the second ST derivative */ static struct pl031_vendor_data stv2_pl031 = { .ops = { .read_time = pl031_stv2_read_time, .set_time = pl031_stv2_set_time, .read_alarm = pl031_stv2_read_alarm, .set_alarm = pl031_stv2_set_alarm, .alarm_irq_enable = pl031_alarm_irq_enable, }, .clockwatch = true, .st_weekday = true, /* * This variant shares the IRQ with another block and must not * suspend that IRQ line. * TODO check if it shares with IRQF_NO_SUSPEND user, else we can * remove IRQF_COND_SUSPEND */ .irqflags = IRQF_SHARED | IRQF_COND_SUSPEND, .range_min = RTC_TIMESTAMP_BEGIN_0000, .range_max = RTC_TIMESTAMP_END_9999, }; static const struct amba_id pl031_ids[] = { { .id = 0x00041031, .mask = 0x000fffff, .data = &arm_pl031, }, /* ST Micro variants */ { .id = 0x00180031, .mask = 0x00ffffff, .data = &stv1_pl031, }, { .id = 0x00280031, .mask = 0x00ffffff, .data = &stv2_pl031, }, {0, 0}, }; MODULE_DEVICE_TABLE(amba, pl031_ids); static struct amba_driver pl031_driver = { .drv = { .name = "rtc-pl031", }, .id_table = pl031_ids, .probe = pl031_probe, .remove = pl031_remove, }; module_amba_driver(pl031_driver); MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>"); MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver"); MODULE_LICENSE("GPL");